KR20120051359A - Method for producing powder type paste vinyl chloride-based resin having excellent processing property - Google Patents

Abstract

PURPOSE: A manufacturing method of a powdery paste vinyl chloride-based resin is provided to provide a powdery paste vinyl chloride-based resin having excellent foaming properties and low viscosity change after hardening through a drying process of polymerized latex. CONSTITUTION: A manufacturing method of a powdery paste vinyl chloride-based resin comprises a step of drying vinylchloride-based latex within 61-72 °C. In case the vinylchloride-based latex is manufactured by seed emulsion polymerization, drying temperature is 61-66 °C, and in case the vinylchloride-based latex is manufactured by emulsion polymerization, drying temperature is 67-72 °C. The seed for seed emulsion polymerization is vinyl chloride-based resins which are different kinds of a seed with small average particle diameter and a seed with large particle diameter. The seed with small average particle diameter is 0.1-0.25 micron.

Description

{Method for producing powder type paste vinyl chloride-based resin having excellent processing property}

The present invention relates to a method for producing a powdery paste-vinyl chloride-based resin having excellent workability. More specifically, the present invention relates to a powdery-paste vinyl chloride having little change in viscosity over time and excellent foaming properties through controlling the drying process of polymerized latex. It relates to a method for producing a system resin.

The vinyl chloride paste resin prepared by microsuspension polymerization, seed emulsion polymerization, emulsion polymerization, or the like may be obtained through a drying process of vinyl chloride latex. The resin thus prepared is mixed with a plasticizer and other additives and processed into a plastisol form to be used.

Since the plastisol contains a large amount of vinyl chloride-based resin and additives, the physical properties of the product also vary depending on the content and type thereof. In particular, the plastisol is gradually increased in viscosity due to plasticization of the vinyl chloride resin. This is because the vinyl chloride-based resin is agglomerated with the primary particles and more particles, and the plasticizer penetrates therebetween.

In order to prevent this, there is a method of slowing the plasticization of the particles or reducing the area of the particles.

Accordingly, the inventors of the present invention have been trying to find a method of easily adjusting and improving the properties of the resin differently from the method of controlling subsidiary materials and additives introduced during polymerization or plastisol processing. It has been found that not only can the aggregation of particles be increased through the increase, but also the reduction of the surface area of the particles can be achieved to achieve a low rate of change over time, and the present invention has been completed.

That is, an object of the present invention is to increase the viscosity of the plastisol produced by using a powdered paste vinyl chloride-based resin having a small change in viscosity over time and excellent foaming properties by controlling the drying process of the polymerized latex. The aim is to solve the difficulties in conveying and processing and to improve the foaming properties.

According to the present invention, there is provided a method for producing a powdery paste vinyl chloride-based resin, characterized in that the vinyl chloride-based latex is dried within the range of 61 to 72 ℃.

In addition, the vinyl chloride-based latex is dried within the range of 61 to 72 ℃ to prepare a powdery paste vinyl chloride-based resin, and then a paste sol is prepared by adding an additive including a blowing agent and a plasticizer, characterized in that the plastic degassing Provided are methods for the preparation of styrene.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention has a technical feature to lower the rate of change over time and improve the foaming properties by controlling the agglomeration degree of the particles of the vinyl chloride-based latex through the drying process temperature control.

In the present invention, the composition and polymerization conditions of the reaction mixture including the vinyl chloride monomer are not described in detail because they can be easily adjusted by the average person skilled in the art as needed. However, for example, a) water in an amount such that the concentration of the vinyl chloride polymer is 20 to 75% by weight relative to 100 parts by weight of the vinyl chloride monomer c) 1 to 10 parts by weight of the polymerized seed latex, d) 0.001 to 2.0 parts by weight of a polymerization initiator, and e) 0.2 to 3 parts by weight of an emulsifier can be prepared by emulsion polymerization.

As the vinyl chloride monomer of a) used in the present invention, vinyl chloride alone, as well as a conventional vinyl chloride monomer copolymerizable with vinyl chloride may be used. Specifically, vinyl acetate, acrylate esters, methacrylate esters, olefins such as ethylene and propylene, unsaturated fatty acids such as acrylic acid, methacrylic acid, itaconic acid and maleic acid or anhydrides of these fatty acids may be used as copolymerization monomers. Can be.

As water of b) used in the present invention, deionized water from which ion particles are removed by ion exchange or the like may be used.

The seed latex of c) is preferably used by mixing one or more species of latex particle having different sizes, especially seed latex having an average particle diameter of 0.1 to 0.25 µm and seed having an average particle diameter of 0.4 to 0.7 µm. It is preferable to use a bimodal type in which latex is mixed, and more preferably, a bimodal type in which seed latex having an average particle diameter of about 0.2 μm and seed latex having an average particle diameter of about 0.6 μm is used. good.

In this case, it is preferable that the amount of the mixed use is in the particle loading ratio of the seed having a small average particle diameter and the seed having a large average particle diameter in a range of 0.65 to 1.52. If the ratio is less than 0.65, it is not preferable in view of the foaming properties of the flooring resin, that is, there is a problem that it is difficult to use for flooring because the foaming ratio is low because the content of small particles is too low, the cell is rough, 1.52 If exceeded, the viscosity becomes too high, making the manufacturing and processing of the plastisol difficult, and the rate of change of viscosity with time also increases, which is also undesirable.

The seed latex is preferably contained in 1 to 10 parts by weight with respect to 100 parts by weight of the vinyl chloride monomer, when the content is less than 1 part by weight has a problem that the polymerization reactivity is lowered, productivity may be lowered, 10 parts by weight If it exceeds, there is a problem that the reaction is intense and heat of reaction heat is difficult.

There is no restriction | limiting in particular as d) polymerization initiator used for this invention, A normal oil-soluble initiator and a water-soluble initiator can be used. Specifically, the oil-soluble initiator is dipentyl peroxide, di-3,3,5-trimethylhexane oil, dilauroyl peroxide, diisopropyl peroxy dicarbonate, di-tert-butyl peroxy dicarbonate, di- 2-ethylhexyl peroxy dicarbonate, azobisisobutyronitrile, azobis-2-methylbutyronitrile, or azobis-2,4-dimethylvaleronitrile, and the like, and water-soluble initiators include potassium persulfide, Ammonium persulfide or hydrogen peroxide. The polymerization initiator is preferably included in an amount of 0.001 to 2.0 parts by weight based on 100 parts by weight of the vinyl chloride monomer. When the content is less than 0.001 parts by weight, there is a problem that the polymerization reactivity is lowered. There is a problem that it is difficult to remove the heat of polymerization reaction apart from each other.

In one embodiment of the present invention, the polymerization time is shortened by controlling the initial reactivity using a redox initiator system. In one specific embodiment, the redox initiator is preferably copper sulfate and ascorbic acid. In addition, KPS and LPO can be used. When the vinyl chloride-based resin is manufactured by an isothermal reaction method while controlling the initial reactivity by using the redox initiator, the reaction stability is improved, the foaming properties are improved, and the reaction time can be shortened.

The emulsifier of e) used in the present invention may be used a conventional emulsifier. For example, Alkylbenzene sulfonates, such as sodium dodecyl benzene sulfonate, as an anionic emulsifier; Alkyl sulfates such as sodium lauryl sulfate and sodium tetradecyl sulfate; Sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium dihexyl sulfosuccinate; Fatty acid salts such as sodium lauryl acid and semi-hardened potassium potassium fat; Ethoxy sulfates such as sodium polyoxyethylene lauryl ether sulfate and sodium polyoxyethylene nonylphenyl ether sulfate; Alkanesulfonates; Alkyl ether phosphate ester salt, etc. are mentioned. There is no restriction | limiting in particular in the usage-amount of an emulsifier, Although it can select suitably, Usually, it is preferable that it is 0.2-2.5 weight part per 100 weight part of vinyl chloride monomers. In addition to the anionic emulsifier, nonionic emulsifiers such as polyoxyethylene nonylphenyl ether and polyoxyethylene sorbitan lauryl ester can also be used in combination. It is also possible to add a lipophilic co-emulsifier.

In the present invention, a reaction mixture is prepared and then polymerized. In this case, any polymerization method such as seed emulsion polymerization, emulsion polymerization, or microsuspension polymerization may be used as long as vinyl chloride latex can be produced.

The vinyl chloride-based latex after the polymerization reaction is then dried under a temperature of 61 to 72 ° C., such as spray drying, to obtain a vinyl chloride powder paste. In this case, when the vinyl chloride-based latex is prepared by seed emulsion polymerization, the drying temperature is more preferably within the range of 61 to 66 ° C, and more preferably within the range of 67 to 72 ° C when prepared by emulsion polymerization.

The temperature range is a form of particles of a harder structure by increasing the dry drying temperature, the plasticizer is hardly penetrated, so that all ratios are low, and also because the water content remaining in the resin is reduced, foaming properties are also improved. It is set in consideration. Particularly, when the temperature exceeds 72 ° C., a latex feed rate may be very slow and may not be transported after drying, and less than 61 ° C. is not preferable because the ratio of aging is relatively high and foam cells are less dense.

In the powder paste vinyl chloride resin thus obtained, a plastisol is prepared and foamed with an additive including a blowing agent and a plasticizer to solve the difficulty of conveying and processing due to the viscosity increase with time of the conventional plastisol, and to improve the foaming properties. It can be improved.

The additives usable herein include, for example, heat stabilizers, fillers, foaming agents, foaming accelerators, surfactants, viscosity reducing agents, tackifiers, colorants, diluents, ultraviolet absorbers, antioxidants, reinforcing agents, other resins, and the like. Plastisol can be prepared by mix | blending these as needed and mixing them so that it may become homogeneous enough, using a planetary mixer, a kneader, a roller, a dissolver, etc.

The plasticizer used at this time is not particularly limited, and for example, dibutyl phthalate, diisobutyl phthalate, diheptyl phthalate, di- (2-ethylhexyl) phthalate, diphthalic acid-n-octyl, dinonylphthalate, diiso Phthalic acid derivatives, isophthalic acid derivatives, adipic acid derivatives, sebacic acid derivatives, maleic acid derivatives, trimellitic acid derivatives, fatigue Melitric acid derivatives; Itaconic acid derivatives, oleic acid derivatives; Phosphoric acid derivatives, glycol derivatives, glycerin derivatives, adipic acid polyesters, sebacic acid polyesters and the like can be used. These plasticizers can be used individually by 1 type or in combination of 2 or more type. The compounding amount of the plasticizer can be appropriately adjusted according to the person skilled in the art according to the application. In addition, but not limited to this, 55 parts of dioctylphthalate as a plasticizer in 100 parts by weight of the powdery paste vinyl chloride resin, as used in the following examples. 2 parts by weight of blowing agent, 10 parts by weight of viscosity reducing agent, 2.5 parts by weight of stabilizer and 80 parts by weight of filler were added, stirred at 500 rpm for 10 minutes, and then mixed at 800 rpm for 10 minutes to prepare a paste sol, followed by vacuum defoaming to form a plastisol. You can also make.

The plastisol prepared by the present invention is characterized by satisfying the foaming ratio of 4.25 to 4.40, and the foaming degree of whiteness of 32.17 to 35.11. In addition, the paste sol is characterized in that the time-lapse ratio value calculated from the following formula satisfies the range of 1.11 to 2.25.

(a: viscosity with time measured after 3 days of paste sol (cp), b: initial viscosity of paste sol (cp))

The powder paste vinyl chloride resin of the present invention is mixed with a vinyl chloride resin for mixing having an average particle diameter of 10 to 60 µm, known as a mixed resin, a dilute resin, or the like, for the purpose of improving the hardness and glossiness of a molded article, and adjusting the paste. It may be.

According to the above, there is no additional input of additives or additives and can be improved only by changing the drying temperature, which is easy to control and has advantages in terms of production. In addition, it can be effective in all cases irrespective of the polymerization method and all have the same effect without being affected by the drying method.

According to the method of the present invention, through the control of the drying process of the polymerized latex to prepare a powder-paste vinyl chloride-based resin with a small change in viscosity over time and excellent foaming properties, from which the transfer due to the increase in viscosity of the plastisol over time And it can solve the difficulty of processing and improve the foaming properties.

1 is a cross-sectional view of the foam cells of each of the foam specimens prepared according to Examples 1 to 3 of the present invention with an optical microscope (Nikon SMZ 1500 model), a) is Example 1, b) is Example 2, c) is the result of Example 3.
Figure 2 is a cross-sectional view of the foamed specimen foam cells prepared according to Comparative Examples 1 to 3 using a vinyl chloride resin dried at a lower drying temperature than the present invention with an optical microscope, a) is a comparative example 1, b) Example 2, c) is a result of the comparative example 3.

In the following Examples, in order to help the understanding of the present invention, the viscosity and foaming properties over time were confirmed by changing the drying temperature for each content and polymerization method of particles added to the latex.

The dryer used in this experiment was spray-based, bimodal latex and unimodal latex through emulsion polymerization. The vinyl chloride-based resins produced by controlling the drying temperature were mixed with a plasticizer and an additive to prepare a plastisol, and then the viscosity change was measured for 3 days, and foamed specimens were prepared to confirm foaming properties.

< Example  One: Vinyl chloride  Latex and Powdery  Manufacture of Paste Vinyl Chloride Resin 1>

141 kg of deionized water and 185 kg of vinyl chloride monomer were mixed in a 500 L high pressure reactor, and then seed emulsion polymerization was performed at 54 ° C. under a high pressure reactor for 6 hours to prepare vinyl chloride latex. At this time, the seed was seeded with an average diameter of 0.19 μm and a seed with an average diameter of 0.66 μm such that the usage ratio (small seed amount / large seed amount) satisfies 0.65.

The vinyl chloride latex thus obtained was adjusted to an outlet temperature of 65 ° C. in a spray dryer and dried to obtain a vinyl chloride resin.

< Example  2: Vinyl chloride  Latex and Powdery  Manufacture of Paste Vinyl Chloride Resin 2>

A vinyl chloride latex and a powdery paste vinyl chloride resin were prepared in the same manner as in Example 1 except that the seed usage ratio was 1.09.

< Example  3: Vinyl chloride  Latex and Powdery  Manufacture of Paste Vinyl Chloride Resin 3>

A vinyl chloride latex and a powdery paste vinyl chloride resin were prepared in the same manner as in Example 1 except that the seed usage ratio was 1.52.

< Example  4: Vinyl chloride  Latex and Powdery  Manufacture of Paste Vinyl Chloride Resin 4>

After mixing 53 kg of deionized water and 66 kg of vinyl chloride monomer in a 200 L high-pressure reactor, the mixture was emulsified and polymerized at 50 ° C. for 6 hours at 60 ° C. for 1 hour. The vinyl chloride latex having an average particle diameter of 0.13 μm was obtained. Prepared. The vinyl chloride latex thus obtained was adjusted to an outlet temperature of 72 ° C. in a spray dryer and dried to obtain a vinyl chloride resin.

< Comparative example  1: drying temperature adjustable 1>

A vinyl chloride latex and a powdery paste vinyl chloride resin were prepared in the same manner as in Example 1 except that the outlet temperature of the spray dryer was 60 ° C.

< Comparative example  2: drying temperature adjustable 2>

A vinyl chloride latex and a powdery paste vinyl chloride resin were prepared in the same manner as in Example 2 except that the outlet temperature of the spray dryer was 60 ° C.

< Comparative example  3: drying temperature adjustable 3>

A vinyl chloride latex and a powdery paste vinyl chloride resin were prepared in the same manner as in Example 3 except that the outlet temperature of the spray dryer was 60 ° C.

< Comparative example  4: drying temperature adjustable 4>

Vinyl chloride-based latex and powdery paste vinyl chloride resin were prepared in the same manner as in Example 4 except that the outlet temperature of the spray dryer was 65 ° C.

< Comparative example  5: after polymerization Non-ion  Example Using Emulsifier>

A vinyl chloride-based latex and a powdery paste vinyl chloride resin were prepared in the same manner as in Example 2 except that 0.8 phm (per hundred monomer) of PEG was added.

< Test Example >

55 parts by weight of dioctylphthalate as a plasticizer, 2 parts by weight of blowing agent, 10 parts by weight of viscosity reducing agent, and 2.5 parts by weight of stabilizer in 100 parts by weight of the powdery paste vinyl chloride resin prepared in Examples 1-4 and Comparative Example 1-5. , 80 parts by weight of a filler was added, stirred for 10 minutes at 500 rpm, and then mixed for 10 minutes at 800 rpm to prepare a paste sol.

From the paste sol, the initial viscosity and the aging viscosity were measured in the following manner, and the ratio of aging was calculated and summarized in Table 1 below. Further, foamed specimens were prepared, and foamed whiteness, foamed cells, and foaming ratio were measured and observed. It is shown as Fig. 1-2.

Initial Viscosity Determination The paste sol was vacuum degassed and stored for 1 hr in a constant temperature and humidity chamber with a temperature of 25 ° C. and a humidity of 50%, followed by a step rate of 0.01 to 100 using a rheometer (AR2000EX stress control type rheometer manufactured by TA instruments). Measured by a sweep test, the viscosity at shear rate 1 was defined as the initial viscosity.

Viscosity Measurement Over Time The paste sol was stored in a constant temperature and humidity chamber at 25 ° C. and 50% humidity for 3 days, and then measured in the same manner as the initial viscosity measurement method using a rheometer (AR2000EX stress control type rheometer manufactured by TA instruments). .

<Time-lapse rate measurement> The time-lapse viscosity measured after 3 days was calculated by dividing the initial viscosity.

< Measurement of Foam Specimen Whiteness> The paste sol was degassed in vacuum to coat 0.5 mm of plastisol on the OHP film. The specimen was foamed at 205 ° C. for 2 minutes. The prepared specimen was placed on a white paper and measured using a color difference meter.

<Observation of the foam cell> Foamed specimens were cut to size and visually compared using an optical microscope.

<Calculation of expansion ratio> The coating thickness was measured and then foamed, followed by the foam thickness. Foam thickness was calculated by dividing the coating thickness.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Seed Usage Ratio * 0.65 1.09 1.52 Emulsion polymerization 0.65 1.09 1.52 Emulsion polymerization 1.09 Dryer outlet temperature (℃) 65 65 65 72 60 60 60 65 65 PEG Usage
(phm) - - - - - - - - 0.8 Initial viscosity (cp) 6564 7750 9451 27430 5850 6460 8135 19850 8886 Chronological
(cp) 7614 9068 11980 61720 7908 8915 11515 58900 10220 Percentage Ratio 1.16 1.17 1.27 2.25 1.35 1.38 1.42 2.97 1.15

* Seed usage ratio = seed with small average particle diameter / seed with large average particle diameter

As shown in Table 1, in Examples 1 to 4 prepared according to the present invention, all ratios of aging were much lower than those of Comparative Examples 1 to 4. This is believed to be due to the rise of the dry drying temperature to form a harder particle form, which hardly penetrates the plasticizer.

On the other hand, in the case of Comparative Example 5 using a plasticizer at the time of drying according to the conventional method, the effect of significantly improving the viscosity elapse rate compared to the case of Examples 1 to 4 of the present invention could not be obtained. On the contrary, it can be seen that the viscosity change range is somewhat larger in the case of Comparative Example 5. In addition, the use of nonionic emulsifiers did not yield foam cells suitable for floor foaming.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 5 Expansion ratio 4.25 4.34 4.40 4.11 4.18 4.38 Not measurable Foam white 32.17 33.52 35.11 30.22 31.98 34.93 28.54

As shown in Table 2, in the case of Examples 1 to 3 prepared according to the present invention it was confirmed that the foam properties are all improved than the case of Comparative Examples 1 to 3, 5. This is believed to be due to the decrease in the moisture content remaining in the resin.

On the other hand, in the case of Comparative Example 5 using a plasticizer when drying according to the conventional method compared to the case of Examples 1 to 3 of the present invention, the foaming ratio could not be measured because the foaming surface was not smooth due to over-foaming. As a result, the foamed white color was also deteriorated.

In addition, as shown in the optical microscope observation results of FIGS. 1 and 2, in Examples 1 to 3 using resins having a high drying temperature, it was confirmed that the foam cells were denser than Comparative Examples 1 to 3.

Claims (13)

A method for producing a powdery paste vinyl chloride resin, characterized in that the vinyl chloride latex is dried within the range of 61 to 72 ℃. The method of claim 1,
When the vinyl chloride-based latex is prepared by seed emulsion polymerization, the method of producing a powdery paste of vinyl chloride-based resin, characterized in that the drying at 61 to 66 ℃. The method of claim 1,
When the vinyl chloride-based latex is prepared by emulsion polymerization, the method for producing a powdery paste of vinyl chloride-based resin, characterized in that the drying at 67 to 72 ℃. The method of claim 2,
The seed emulsion polymerization seed is a method for producing a powdered paste vinyl chloride-based resin, characterized in that the two types of vinyl chloride-based resin having a seed having a small average particle diameter and a large seed. The method of claim 4, wherein
The average particle size of the seed having a small average particle diameter is a method for producing a powdery paste vinyl chloride resin, characterized in that in the range of 0.1 ~ 0.25 ㎛. The method of claim 4, wherein
The average particle size of the seed having a large average particle diameter is a manufacturing method of the powdery paste vinyl chloride resin, characterized in that in the range of 0.4 ~ 0.7 ㎛. The method of claim 4, wherein
The particle-feed ratio of the seed having a small average particle diameter and the seed having a large average particle diameter is in the range of 0.65 to 1.52. The method of claim 1,
The drying step is a method for producing a powdery paste vinyl chloride resin, characterized in that the addition of additional ingredients or additives is excluded. The vinyl chloride latex was dried within a range of 61 to 72 ° C. to prepare a powdery paste vinyl chloride resin, and then a paste sol was prepared by adding an additive including a blowing agent and a plasticizer, and then vacuum defoaming. Method of preparation. The method of claim 9,
When the vinyl chloride-based latex is prepared by seed emulsion polymerization, it is dried at 61 to 65 ℃ method for producing a plastisol. The method of claim 9,
When the vinyl chloride-based latex is prepared by emulsion polymerization, a method for producing a plastisol, characterized in that the drying at 66 to 72 ℃. The method of claim 9,
The plastisol has a foaming ratio of 4.25 to 4.40, and foaming whiteness of 32.17 to 35.11 to satisfy the method of producing a plastisol. The method of claim 9,
The paste sol is a method of producing a plastisol, characterized in that the time-lapse ratio value calculated from the following formula is in the range 1.11 to 2.25.
[Equation 1]
Lapse ratio = a / b
(a: viscosity with time measured after 3 days of paste sol (cp), b: initial viscosity of paste sol (cp))

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